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Biomedical subjects

R J Lane

Publications and source records attributed to R J Lane.

At least 73 records · Page 4Linked to original sources
PubMed1988

Cyclosporin neurotoxicity in cardiac transplant recipients.

Cyclosporin toxicity may produce a wide range of neurological disorders. We report three patients whose neurological problems developed while taking cyclosporin following cardiac transplantation, but resolved rapidly when the drug was discontinued. In two cases, MRI revealed abnormalities which disappeared with clinical recovery. Blood cyclosporin concentrations were not markedly increased, and it is possible that the neurotoxic effects of cyclosporin are mediated by metabolites, through an effect on the blood-brain barrier.

Adolescent↗
PubMed1987

Ultraviolet laser ablation of skin: healing studies and a thermal model.

We have followed the course of healing of incisions made with the krypton-fluoride excimer laser. Incisions were made in guinea pig skin, in vivo, under identical conditions of irradiation. The progressive healing of these incisions was followed over the course of 3 weeks. We noted excellent healing with re-epithelialization, and the re-formation of collagen fibers with minimal fibrosis. We present a simple thermal model for ablation of tissue by a short pulse of strongly absorbed laser radiation.

Animals↗
PubMed1987

Absence of biochemical heterogeneity in McArdle's disease. A high resolution SDS-polyacrylamide gel electrophoresis study.

Muscle biopsy extracts from a series of 6 patients with McArdle's disease were investigated by analytical SDS-polyacrylamide gel electrophoresis, to establish the presence or absence of the myophosphorylase protein subunit. In 4 cases, the band corresponding to the myophosphorylase subunit was totally absent from the electrophoretic staining pattern, and in 2 cases was present, but with a greatly reduced staining intensity compared with control normal patients; thus in none of the cases of McArdle's disease investigated was there evidence for a myophosphorylase subunit band of comparable staining intensity to that found in control normal patients. This result contrasts with previously reported findings (Feit and Brooke 1976) which suggested that McArdle's disease exists in biochemically heterogeneous forms; in one form of the disease myophosphorylase being totally absent and in a second form present to a similar extent as normal, but in an inactive form. On the basis of the results reported in this paper, we would suggest that myophosphorylase deficiency is a single gene disorder characterized by the absence or marked reduction of the myophosphorylase protein.

Adolescent↗
PubMed1986

A double-blind, placebo-controlled, crossover study of verapamil in exertional muscle pain.

Eleven patients, comprising three cases of McArdle's disease and eight with an exertional muscle pain syndrome (EMPS) of unknown cause, entered a double-blind crossover study of verapamil and placebo. None of the patients with McArdle's disease responded to verapamil, but two patients with unclassified EMPS experienced a striking improvement in symptoms and two others showed a partial response. No patient responded to placebo. Six of the eight cases with unclassified EMPS, including the four patients who responded to verapamil, had symptoms that indicated possible abnormalities of muscle metabolism, and four showed nonspecific biochemical, electromyographic, and muscle biopsy abnormalities. The two other EMPS patients had symptoms that suggested that a primary muscle disease was unlikely. They showed no laboratory evidence of muscle disorder, but had abnormal profiles on personality (MMPI) testing. Calcium antagonists, such as verapamil, may be useful in the treatment of some patients with benign exertional myalgia, but the mechanism of action of the drug in such cases is unclear.

Adult↗
PubMed1985

Opiate-induced rhabdomyolysis.

Three patients with opiate self-poisoning developed acute muscle damage with elevated serum aspartate aminotransferase and creatine kinase activities, increased serum myoglobin concentrations, raised plasma creatinine concentrations, hypocalcaemia and hyperphosphataemia. These abnormalities gradually resolved over 7-10 days, but recovery was complicated due to the development of acute renal failure (requiring haemodialysis) in one patient. Plasma drug concentrations, shortly after admission, in the patients taking dihydrocodeine and morphine were grossly elevated (184 and 60 micrograms/l respectively). Clinical evidence of myopathy was minimal in all three patients and muscle biopsy of one patient was normal at 7 days.

Acute Kidney Injury↗
PubMed1985

Ultraviolet-laser ablation of skin.

We report on the use of pulsed ultraviolet-laser irradiation at 193 nm from an argon-fluoride laser and at 248 nm from a krypton-fluoride laser to ablate skin. In vitro, both wavelengths performed comparably, removing tissue precisely and cleanly, and leaving minimal thermal damage to the surrounding tissue. In vivo, the 193-nm laser radiation failed to remove tissue after bleeding began. The 248-nm radiation, however, continued to remove tissue despite bleeding and left a clean incision with only minimal thermal damage. The krypton-fluoride excimer laser beam at 248 nm, which should be deliverable through a quartz optical fiber, has great potential as a surgical instrument.

Animals↗
PubMed1984

Measurement of phosphate concentration in the presence of very labile phosphate esters.

There are a number of methods available for the measurement of phosphate ion concentration, which may be used when moderately labile phosphate esters such as ATP are present in low concentration. However, the highly acidic conditions usually employed make these unsuitable when very labile esters such as phosphocreatine are present. A method in which the phosphomolybdate complex is developed under mildly acidic conditions, using high molybdate concentrations to counteract the reduced assay sensitivity at high pH, is described. The assay is linear in the range 5-300 microM phosphate, and micromolar concentrations of phosphate can be reliably measured in the presence of millimolar phosphocreatine.

Adenosine Triphosphatases↗
PubMed1983

The genetic status of mothers of isolated cases of Duchenne muscular dystrophy.

Classical genetic theory, based on assumed equal mutation rates in males and females, predicts that one-third of all cases of Duchenne muscular dystrophy (DMD) in a generation are born as new mutants to non-carrier mothers. Furthermore, less than half the mothers of apparently isolated cases appear to be carriers on the basis of raised serum creatine kinase levels. We have analysed the pedigrees of 61 families of DMD boys seen in the Duke Neuromuscular Research Clinic and 45 DMD families followed at the University of Virginia. The frequency of affected boys among the next born male sibs of 37 initially isolated DMD cases in two clinic populations was significantly greater than predicted by Haldane's theory (p = 0.029) and the estimated proportion of new mutant cases in the combined clinic population of 106 families was 0.127 (SE 0.111). The absence of affected males in earlier generations in families of isolated cases may be explained in part by a high ratio of male to female stillbirths and infant deaths, which was more than three times that of the normal population in this study. These data suggest that new mutant cases are less common than expected and current predictions may underestimate genetic risks in mothers of isolated cases.

Adult↗
PubMed1983

Lymphocyte capping in myotonic dystrophy.

Lymphocyte capping with antihuman immunoglobulin was studied in 16 cases of myotonic dystrophy, including two cases with the congenital form. Percentage capping after 1 hour incubation was reduced and the time course of the capping sequence was apparently delayed. The significance of these findings remains to be determined.

Adolescent↗
PubMed1983

Polyneuropathy in occult hypothyroidism.

A patient who developed symptoms and signs of a polyneuropathy was found to have hypothyroidism, though this diagnosis was not clinically suspected. Treatment with thyroxine resulted in resolution of his symptoms and restored his nerve conduction studies to normal.

Humans↗
PubMed1983

Drug-induced neurological disorders.

When a patient presents with a neurological or neuromuscular disorder, it is essential to consider drugs as a possible cause. Drugs can affect virtually any part of the neuraxis and the resulting disorders can usually be classified in terms of the anatomical site affected and the clinical presentation. In general, the signs and symptoms of drug-induced neurological disorders are virtually indistinguishable from those seen in naturally occurring disease but are usually reversible if diagnosed early enough. Cortical depression may produce coma, particularly in overdose cases, but a large number of drugs can also initiate seizures in susceptible individuals. The effects of drugs in the pathogenesis of headaches are certainly underestimated, and the eye, hearing and balance mechanisms can be severely damaged by certain drugs before symptoms prompt investigation. The long term effects of antipsychotic drugs on basal ganglia demand that these drugs are used only when absolutely essential and for as short a period as possible. Finally, there is increasing awareness of the role of drugs in the development of neuromuscular disorders such as peripheral neuropathies, myasthenic syndromes and myopathies.

Basal Ganglia Diseases↗
PubMed1983

Immunological studies in myotonic dystrophy.

Abnormalities of cellular and humoral immunity have been recognised in myotonic dystrophy but their significance is uncertain. To throw further light on this, a group of 22 patients with myotonic dystrophy was investigated, looking specifically for evidence of abnormalities of B lymphocyte function and of disturbed immunoregulation. The previously reported reduction in serum IgG levels was confirmed and, in addition, serum IgA levels were significantly reduced. Autoantibodies to muscle and non-muscle antigens were not found and there was no increase in autoimmune disease or malignancy, suggesting that immunoregulatory mechanisms are not disturbed. The proportions of T and B cells were not significantly different in patients and controls. B-lymphocyte capping with FITC- antihuman IgG was quantitatively altered, the percentage of capped cells after incubation being reduced and the time-course of the capping process being apparently prolonged in the myotonic dystrophy subjects. While there are a number of possible explanations for these findings, they may reflect an intrinsic abnormality of the lymphocyte membrane. This could be part of a more generalised membrane defect which has been suggested to underlie the myotonia and certain other manifestations of this multisystemic disorder.

Adolescent↗
PubMed1982

Thymectomy in late-onset myasthenia gravis.

Between 1977 and 1979, 12 consecutive patients with myasthenia gravis who were over the age of 55 years were treated by thymectomy. In all, their conditions improved clinically; 11 of the 12 became free of the generalized features of myasthenia gravis. Nine patients required no further medication. Acetylcholine-receptor antibody titers did not change significantly. Although five patients had atrophic thymus glands, their conditions also improved. We conclude that (1) thymectomy is a safe and effective therapy for patients with myasthenia gravis who are over the age of 55 years; (2) steroids and anticholinesterase agents are not essential in the management of late-onset myasthenia gravis; and (3) reduction in acetylcholine-receptor antibody titer is not essential for beneficial clinical response.

Aged↗